Machine for heating and bending metallic printing plates, such as electrotype and stereotype plates



, SUCHYAS C. N. SMITH MACHINE FOR HEATING AND BENDING METALLIC PRINTING PLATES ELECTROTYPE AND STEREOTYPE PLATES Filed May 5, 1924 Passed Aug. 30, 1927.

CHRISTIAN, N. SMITH, or ELGIN, ILniN rorrrns, o FELGZN, ILLINOIS' nxno'ornrcss or earn CHEF;

MACHINE FOR HEATING AND BEN'DING ELECTROTYPE AND S TER-EOTYPE PLATES.

Application filed m 5,

This invention relates to that class of ma: chines for heating and bending metallic printing plates, whereby metallic printing plates, such a I plates may-be heated andbent into suitably curved form for use in printing. I a

The principal object 'of'the invention 1s" to provide a simple, economical and efficient machine for heating and bending .metallie printing plates, such electrotype or stereotype plates.

Other and further objects of the invention will appear from the following description andclaims, and from an inspection of the accompanying drawings, which are made apart of this specification.

The invention consists in the features, combinations, details of construction and arrangement of parts, herein described and claimed. 1 I

In thev accompanying drawings Figure 1 is a view in front elevation ofa printing-plate bending machine constructed in accordance with my invention, andadapted to be used for heating. and bendingme- I tallic printing plates in accorda ce witlr-my improved-process 'orptherwise as desired, the hollow heating roll being shown in "ertieal section; 4

Fig. 2 is a view in side elevation of the machine shown in Fig. 1, with parts broken away and the driving worm and worm wheel and their supports omitted for elearness of illustration Fig. 3 is a detail view in perspective of a hollow heating and bending rolhwith a metallic printing plate, compressible matrixforming sheet material, flexible outerand intermediate metallic platesfand intermediate sheets of compressible material between the outer metallic backing plate and intermediate metallic sheet as well as between the intermediate metallic sheet and the metallic printing plate to be operatedon such'as are also shown between the bending rolls'in Fig. 1, in position uponathe hollow heating and bending roll of my-impro'ved bending n..- chine; and I Fig.4; is a detail view in side elevation showing the perforated end portions of the hollow heating andbending roll, and means sir/11TH,

s electroty-pe and stereotype {PATENT 1 oFFiCE ors, AssIGNoB or ONE-HALF To WILLIAM r.

ME sMI'rrr 'Ann-LILrrn-Enr: SMITH nnonasnn.

METALLIC"IRINTING PLATES, SUCH AS 1924. Serial No. 711,297.

for opening and closing or controllingythe gas and air inlets to the interior'of the heating roll or combustion chamber.

ln constructing amachine for heating and bending metallic printing plates, such. as

electrotype and-stereotpye plates, in accordance with my invention; 1 provide a main frame 1, which may be of any desired ordinary and well known or suitable form adapted to support-the working parts of the ma;- chine; The frame shown in the drawings is provided with upright side frame members 2 and 3 hired to and extending upward from a bed or table a which has legs 5 of suitable size and strength to form a strong and rigid support for the bed or table. Suitable up-:

rights or standards 6 and 7' are fixed to and extend upward from the bed in position to support a driving shaft- 8 which is journaled' in suitablebearings 9, insaid standardsb Fixed to the rotative main driving and 7. v shaft 8 is a gear orfiworm wheel '10 which may be of any desired well known o'r suite.

able form of gear wheel or driving means adapted to be connected with a suitable. source of power. mechanism of any desired ordinary and well known or suitable-form, not shown, may, be provided for connecting and disconnecting the shaft 8 orwheel 10 with the source of power or with each other. In the form of. the device here shown, however, the gear 10 is a worm wheel fixed to the shaft 8 and in toothed engagement with a worm or. screw 11 whichis fixed to a worm shaft12 jour- And suitable clutch.

.naled in suitable bearings 13 on a frame member or standard it. The worm wheel 10 and worm 11 are thus located-between the standards 6 and 7 which rot-ativelysupportthe driving shaft 8 in position to be connected with and disconnected from the hollow heating and bending roll or rolls of any desired or various dimensions to be operated." 3

'Removably mounted" and journaled in suitable bearings in the standards or frame members 2 and 3 is a hollow heating and bending roll 15 having a curved or oylindrica l outer wall 16, end walls 17 and 18,

hollow hubs 'or journals or axle members 19,

'20, and end flanges, plates or hub members 21, 22. The end wall or head 17 at one end of the roll 15 is removably mounted in the end of the cylindrical or outer peripheral wall of the heating and bending roll which is provided with a suitable annular recess,

annular flange 24 and shoulder 25 for engaging and removably holding the said head in place in the end of the roll.

The standards 2 and 3 are each provided with a recess .01" slot 26 having marginal walls 27, 28 adapted to admit the axle or corresponding end journals 19, t-herebetween. And suitable removable bearing blocks or journal bearings 29, 29 are, by i5 preference provided and each mounted in a corresponding slot or recessed portion 26 in the frame, and are adapted to removably support the heating roll 01' rolls in operative position in the frame. 7

Suitable means are provided for detachably connecting the removable hollow heating and bending roll or rolls with the driving shaft 8 or other driving means, in such a manner that the roll or rolls may be removed and replaced without disturbing the driving mechanism and without employing a worm wheel or gear wheel for each roll, and so as to enable heating and bending rolls of different diameters or sizes to be 30 used interchangeably and detachably connectedwith facility successively and interchangeably in any desired order with the driving mechanism. And although any suitable ordinary and well known form of connecting meansor clutch mechanism may be employed which is adapted to suitably detachably connect the axle or journal of the heating roll or rolls with the driving shaft may be employed, 1 have here shown a very simple and efficient clutch mechanism or connecting means for accomplishing this purpose. v

Each hollow heating and bending roll 15 is provided with one or more perforations or recesses 30 in the hub or end plate 22 of such roll or rolls. And one or more bosses,

pins, or equivalent connecting members 31 is or are provided and adapted to engage such recess or recesses or equivalent connecting means, so as to removably and detachably connect the roll or rolls with the drivim shaft. In the form of clutch or connect-ing and disconnecting means here shown, a head or plate 32 is fixed to the shaft 8- and'provided with a perforation 33 for each pin 31, each of said pins being adapted to be moved endwise into and out of an adjacent or corresponding recess or perforation 30 in the end member or flange 22. A convenient means for moving the pin or pins 31 endwise in the apertures 33 and into and out of engagement with the openings 30 in the hub or end member 22 to be detachably connected with or detached from the shaft 8 is here shown. For this purpose a movable clutch member or ring 34 is pro vided and mounted in position to encircle and to be readily moved longitudinally of the shaft 8, said clutch member being, by preference, annular and provided with an annular peripheral groove 35 in operative engagement with which the forked arms 36 of a clutch-operating lever or yoke 37 are mounted. This lever or yoke is supported by means of a bracket arm 33 or other suitable supporting means, mounted in a suit able support, such, for example, as the standard the lever being connected with the fixed support by means of a pivot pin 39 or other suitable means.

Means are provided for heating the hollow heating and bending roll or rolls, which may be of different or varying sizes,'and are interchangeable, and whereby printing plates may be heated and bent to any desired curvature corresponding with the curvature of the roll employed. Each heating and bending roll 15 forms an inner heating or combustion chamber 40. Each roll has an axial opening 41, which, by preference extends through one ofthe journals or hubs and the corresponding end wall of the roll,

for example, through hub 19 and end wall 17 already described.

A fuel supply conduit is provided which communicates with a source of gas or hydrocarbon fuel supply and with the burner located inside of or in position to heat the .ieating or combustion chamber formed by* the roll. The fuel supply conduit consists of or comprises, by preference, a gas or hydrocarbon fuel supply pipe 42 which commu-nicates with the source of fuel supply or gas supply, a conduit or pipe 42 which extends into or through the axial opening a1 and has a cup- 43". on or, by preference, c.e, tachably connected withthe outer end of said pipe 42 into which the innerend of the pipe projects. '1

The pipe 4-2 is, by preference, detached from pipe l2 and roll 15; and the usual air inlet leads into the fuel passage thus formed. Pipe 4-2 is connected with the burner parts inside the roll which are in the form of one or more branch pipes ist each communicating with the inner extremity of the supply pipe 42, or may consist of an extension of said supply pipe located in the combustion chamber or inner heating chamber formed by the hollow roll.

In the form of the device shown in the drawings, a plurality of branch pipes 442 are provided, each having a perforated portion 16 located inside of the hollow roll and near the periphery or outer plateengaging and bending wall 16 of the roll andconnected and communicating with the pipe 42 and the fuel supply passage formed thereby. These perforated pipe portions, of which there may be one or any desired'number, ex-

tend-parallel to theaxis of the hollow roll on the interior of which the burner thus formed by the perforated pipe or pipes is located. Each pipe 15, 'isprovided with a series of suitable perforations 46 through itsperipheral wall; and the perforated vpipe or pipes and the series of perforations therein extend from end to end of the hollow roll inside of and near the periphery of the come roll. r r a The combustion chamber 40, inside of the bustion chamber formed by or inside of the hollow roll, is by preference annular, and is v adapted to permit orcause the heat 'generated within the roll and the combustion chamber formed thereby,'to be provided at engagementwith and which acts to heat and bend the metallic printing plate.

The hollow heating and bending rolls 15+ of which there may be any desired number of varying sizes or different diameters adapted to he used interchangeably as aforesaid are each provided with an inner wall or hollow drum 17 which is by preference approximately cylindrical and'comprises an annular wall which may be made in one integral piece with the outer end wall of the roll, either end wall 19 or end wall 18, or integral with either one or other of the hubs of the roll 15. A verysatisfactory construction of the inner liner or inner drum members, however is shown in the drawings, and comprises a hollow cylindrical or annular drum 17 of sheet metal of less diameter than and spaced apart from the peripheral outer wall of the hollow roll and extending from end to end of the roll on the inside thereof in position to encircle the longitudinal axis of'the roll and form an inner partition wall between the outer wall and the axis of the hollowheating roll. At one end of the drum 47 is provided an inner end wall 48 which may be integral with the inner drum 47; but for convenience and economy in construction the inner end wall LS'is made in a separate piece of sheet metal and provided with an inner annular marginal flange 49 which is fitted snugly in engagement with the adjacent end of the drum 4-7. And a similar'end 'wall 50 is mounted on the inside of the roll and in snugly fitting engagement with the opposite end of the drum 47, of which it may form integral part if'desired, although it is by preference bent to form an annular flange or V I shoulder 51 which fits snugly in engagement with the adj acentiend margin of the annular drum wall 47. The end wall 50 is provided with an outer. peripheral portion 52 i which extends o'utward' from-the drum wallet? to the inner surface of the peripheral wall 16 of the heating roll and may be integral with inner flanged end wall portions 50, 51 which form a closure for the'end of the drum. Or

the inner end wall portion 52 may be in the form of an annular sheet or plate of sheet metal fitted to the end portion of the drum {l7 and extendingito the inner surface of the peripheral'wall 16 of the roll 15 and to and, by preference, in engagement with the inner surface of'the end wall 18 of the roll 15.

" The outwardly projecting annular end.

wall 48 on orattached .to the end margin of the annular wall or inner drum member-47, is dished or concave on its outer side which faces toward the outer end wall 17 of the roll, and is b annular periplieral flange 52"which extends into engagement with the inner surface of the outer peripheral wall 16 of the roll and the inner surface of the end wall'17 at the inner periphery of the outer wall 16 of the 1 roll; but the peripheral margin 53 is so formed as to provide a restricted space or opening 54 between said margin and the adjacent Walls 16, 17 of the roll adapted to perinit the escape of products of combustion from the combustion chamber 40 at the upper extremity of'said chamber through the circumferential peripheral outlet opening or space 54; into the end chamberor space 55 and out through an upper outlet opening or openings 56 in and through the end wall 17 which is provided with one or more, preferably a series'of such openings 56,.

The outlet opening or openings '56 thus permit the escape of products of combustion from the end chamber 55 at a point or points above the level of the air inlet openings 57 in the hub 19 or end'wall of the roll, and

leadinginto'the axial opening 41 and end chamber 55 of which said aXial opening forms a part.

The outlet opening 56 at the highest point at which such openings occur, whether the combustion chamber 40 on the inside of the roll 15 and below the level of the upper inner peripheral outlet opening or space 54 which is at the extreme-upper margin of the eom- 'bustion chamber 40.7 "But the uppermost outlet opening '56 is above the level of the air inlet opening or openings 57. And in the form of the device in which the openings 56 are in the end Wall of the hollow heating roll preference bent to form an which rotates, it is obvious that the lowermost one or more of the outlet openings 56 .will act in the capacity of air inlet openings when below the'level of the air inlet openings 57. i e

From the foregoing. itwill be seen that the heated gases and products of combustion are permitted to escape from the combustion chamber L0 at the upper extremity of said chamber, into the end chamber 55, but can only escape from the latter at a point or points below the level of the upper extremity of the combustion chamber a0, and above the level. of the air inlet opening or openings to the end chamber 55. The heat is thus greatest at the upper extremity ofthe combustion chamber, where the peripheral wall of the heating and bending roll is in contact with and acts to heat and bend the metallic printing. plate to be operated upon,,and is not permitted to escene or be dissipated without first rising to the upper extremity of the heating or combustion chamber. The inner walls 48 and 52 are provided with suitable openings through which the ln rner tubes or pipes extend. ind it will be readily seen that the burner including the branch pipes 45. and the inner drum 4? and inner end wall members- 48, 50, 52 may remain stationary while the roll is rotated in the operation of heating and bending printing plates, although said burner and inner drum me1rhers'and inner end Walls may be permitted to rotate with the roll 15 if desired.

An annularbashing 58 which encircles the supply pipe 42 extends into the axial o-pen ing ll and closes the same, forming a bearin around the pipe 42. The bushing 58 may be threaded and in threaded engagement. with an inner threaded opening in the hub 19, if desired, and isprovided with an annular flange 59 which has perforations 6'0 therethrough, each movable into and out of position to register with corresponding air inlet opening 57 in the hub 19. A very simpleand efficient means for controlling the air inlet openings 57 is thus provided. And it is obvious that the bushing may be caused to move longitudinally of its axis into and out of position to open or close all of the openings 57,. if desired, or may be rotated so as to either partially or completely open or close any opening or openings 57 which are in position to register with the opening or openings 60 in the bushing 58.

I provide one or more auxiliary bending rolls 61 rotatively mounted in the frame of the machine in position to permit the metallic printing plate, backing sheet or sheets and intermediate sheets or material to pass between such roll or rolls 61 and the hollow heating and bending roll 15. Each roll 61 is rotatively mounted with its axis parallel to the axis of the hollow heating'and bending roll 15, and is movable toward and from the roll 15 to different desired or predetermined adjusted positions.

Each roll 61 is provided with an axle or trunnions 62 forming end journals at opposite ends of the roll which are journale-d' in adjustable or sliding bearing blocks 63 slidably mounted between parallel ways or guides 64, 64 formed by the upright standards 2 and 3 respectively adjacent. to. the opposite ends of the rolls 15 and 61, and adapted to guide the latter as it is moved to dilferent adjusted positions. V

1 Suitable means for adjusting the sliding blocks and thereby the roll or r0lls61 is provided, which may be of any desired ordir nary and well known form. For example, each sliding. block 63 is provided with an adjusting screw 65 non-rotatively mounted in or fixed to such sliding block and movable upward and downward With. the block, the upper end portion of each screw 65 being screw-threaded. A toothed beveled gear 69 is mounted in screw-threaded engagement, with each adjusting screw 65, and rotatively supported in a suitable bearing'66 in the corresponding side frame member or stand ard 2, or o as the case may be. Each of'the beveled gears 69 has an annular collar 70 fixed to the lower end of the hub of the gear and adapted to abut against the under side of the bearing 66 so as to permit the rotation of the gear but prevent the movement of the same longitudinally of its axis.

A shaft 71 is rotatively mounted in suit able bearings 68, 68 inthe frame; and beveled gear wheels 72, T2 are fixed tothe opposite ends of said shaft 71 and each in toothed engagement with an adjacent bevel gear 69 already described A. hand wheel or other suitable operating means 73 is mounted on or connected with the shaft 71 the rotation of which in one direction will cause the roll 61 to be raised. It follows as a matter of course that the rotation of the shaft 71 in an opposite direction will cause the roll 61 to be moved toward the roll 15 or lowered. The axes of the rolls 61 and '15 are thus at all times parallel; and heating and bending rolls of differentor varying diameters may be used interchangeably, and the space between the rolls 61. and 15 may be regulated accurately and the roll or rolls 61 adjusted desired.

The. hollow heatingand bending roll is provided with a peripheral printing-plate- .engaging bar 74 which extends longitudinally of the roll and, by preference, fromend to end thereof and in parallel relation to the axis of the roll. v

'ihis plate-holding strip or bar 7a is pro vided with. a side flange 7 5 which projects over a corresponding inner longitudinal marginal notch or recess 76,. which is adapted to receive and removably hold in position the corresponding adjacent marginal. portion or.

edge of a metallicprinting plate,such as an electrotype or stereotype'plate'ZTto be heated and bent. The marginal flange 75 pro-' jects over the adjacent-marginal portion of the metallic printing. plate and acts to removably but firmly hold said margin betweenthe flange and the adjacent peripheral surface of the roll 15 during the-operation of heating andbending the plate. An outer: flexible backing sheetor plate. v78, which 18 by preference, made of flexible sheet metal, extends over the outside of the plate-holding bar 74 and from end to end of said bar, and has its forward edge secured to the pe-.

ripheral surface of the'heating and bending roll v15, or in "engagement with the bar 7st androll, in advance ofthe-sa1d bar by su tablesecurmg means, such, for example, as a securing strip; 74 .riveted in place or-otherdiscarded or, used over again, as may be 'dey wise secured to'the backing plate 7 8 and itssupport, 7'

The. flexible outer .metallic backing: plate orcsheet 78fis'ofisufficient length to completely' or approximately encircle the heating and bending roll on which it is mounted.

Any desired number of intermediategba'ckingsheets of flexible material may be interposed'between the outer metallic backing sheet 7 8,'an'd the metallic printing plate to be-operated upon. For example intermediate sheets 79, 80, 81, 82 and 83, of suitable flexible material are, bypreference, inter- 7 posed :between the printing surface of the metallic printing plateand said outer metallic backing-sheet, as shown in Figs. 3 and 4. The sheet8lwhich is in'contact with the printing surface of the vmetallic-printing plate is, by preference, formed ofpaper pulp or similar compressible'material.

In operation,- a metallic printing; plate,"

such as an'electrotype Ior stereotypeplate, copper printing plate, zincyoraluininum plate, or printing plate of any desired mate-' rial, is provided and covered withalayer,

sheet or sheetsofpaper pulp or similar coIn- I pressible material 81. Suitable intermediate sheets then be interposed between the compressible sheet 81.and' the outer metallic backing sheet, and theroll is then, by preference,'heated, and allof said sheets including the metallic printing plate, are bent si multaneously, byrotating the heating; and bending roll whilesaid sheets are in position to pass between the bending rolls 15 and 61. The bent printing plateand said sheets are then removed and the intermediate sheets sired. And the operation is-repeate'd in the heating and bending of other or similar metallicprlnting plates, as desired,.using the Samehollow heating and bending roll for p as many successive operations-as may be desired; or using hollow heating and bending rolls of 'dliferent diameters or varylng slzes or curvatures interchangeably or as'desired,

From the foregoing description it will be; readily understood by those skilled in the art that hollow heating and bending rolls of different or varying-diameters maybe used interchangeably without disturbing or changing the driving gears or worm and wornrwhee'l mechanism, and whether. the

heating and bending rolls areof cylindrical form orpartially cylindrical and partially. And the heating device flat or segmental. herein shown and described, isadapted to be used, with such modifications as will readily occurto a mechanic skilled in the art and fam1l1ar with the constructlonand operation of machines and methods of heating and bending metallicprinting plates. for heating tainable by other means than that of a burner, preferably a gas burner, inside' off the roll; and that the compressible sheetmaterial should be heated and compressed against the metallic'printing'plate while the compressible material is in a moist or plastic condition; and-that said compressible material should be not only'heated and bent progressively simultaneously withand while in contact with the metallic printing plate, but, by preference, also dried progressively and during the operation of heating'and bending the metallic printing plate, and al{ lowing the latter to cool and set, by preference, while .heldfirmly in place. upon the heating and bending roll. Cooling to a temperature below that which is necessaryto permit or cause the printing plate to set and holdits proper curvature, before removal from: the roll is of course unnecessary.

-Iclaim 1. -In a machine metallic printing plates, the combination of a plurality of parallel rolls including a horizontal rotative hollow heating and bending roll adapted to be interchangedwithothersimilar rolls of different sizes, driving shaft I and gear mechanism for rotating suchinterchangeable hollow heating and bending rolls of different sizes successively, means for for heating and bending heating said hollow heating and bending rolls during the rotation thereof, stationary supporting means adapted to support said rolls in position to rotate upon horizontal axes, and connecting means adapted to detachably connect said driving shaft with hollow heating and vbending rolls successively and acting to permit the removal of any heating and bending roll so detachably coneach of a plurality of such interchangeable nected with said driving shaft independently of and without removing said driving shaft from its support.

'2. In a machine for heating and bending metallic printing plates, the combination of combus ble- 'flflid to said burner, an auxiliary roll rotatively mounted and having its axis in parallel relation to the axis of the hollow heating and bending roll and adapted to' perm-it the passage of a metallic printing plate between the adjacent peripheries of said rolls, to be heated and bent, and means for rotating said rolls,

'3. In a machine for heating and bending metallic printing plates, the combination of a hollow heating and ,bendingro'll forming the outerperipheral w ll of a heating chamher-located wit-hinthe roll, an inner hollow drum located inside of said roll and forming an inner wall of said heating chamber, a burner for heating said chamber, means for supplying fuel to said burner, a driving shaft rotative-ly mounted independently of said roll, for rotating the same, means for rotatively supporting said hollow heating and bending roll independently of and normally out of engagement with said driving mechanism, and means for detachably connecting said driving shaft with the roll and adapted to permit the removal of the roll from its supportindependently ofand without removing the driving shaft from its support. 1

4:. In a machine for heating and bending metallic printing plates, the combination of a hollow heating and bending roll forming an outer peripheral wall of a combustion chamber locatedwithin the roll, a support for said roll, an inner hollow drum located inside of said roll and forming an inner wall of said heating chamber, a burn-er located inside of said roll, for heating said chamber and the periphery of the roll, a fuel supply pipe extending into the end of said roll and connected with said burner, and means for.

detachably connecting said roll with asource of power.

' 5. In a machine for heating and bending metallic printing plates, the combination of fa hollow'heating and bending roll forming an'o'uter peripheral wall of a combustion chamber located inside of the roll, an, inner drum located inside of said roll and forming an inner wall of said combustion chamber, an inner end wall extending between the outer end wall of the roll and the combustion chamber and forming an end chamber inside of the roll, an air inlet 'leading into said end chamber, an outlet leading from the upper portion of the combustion chamber, means, for admitting air from the end chamber into, the combustion chamber, a burner extending into the combustion chamber, and means for supplying fuel to said burner. I

6. In a machine for heating and bending metallic printing plates, the combination or. a hollow heating and bending roll forming a burner extending into the" combustion chamber, and means for supplying fuel to said burner. I 4 v 7Q Ina machine for heating and bending metallic printing plates, the combination of ahollowheating and bending roll forming a combustion chamber, an inner endv wall extending between the outer end wall of the roll and the combustion chamber and forming an end chamber having air inlet and out let openings, a discharge opening leading from the upper portion ofthe combustion chamber into said end chamber, means for admitting air into the combustion chamber at" a point located below the level of said discharge opening from the combustion chamber, a burner extending into said combustion chamber, means for supplying fuel to said burner, and means for rotating the hollow heating and bending, roll. 1

8. In a machine for heating and bending metallic printing plat-es, the combination of a hollow heating and bending roll provided with an annular inner combustion'chamber,

an inner end wall extending between the outer end wall of the roll and the combus tion chamber and forming an end chamber having an outlet opening and an air" inlet opening, a discharge opening located above the level of said outlet opening and leading from the combustion chamber into the end chamber, means'foradmitting air into the combustion chamber, arburner for heating the combustion chamber, and means forsupplying fuel to the burner.

'9. In a machine for heating and bending metallic printing plates, the combination of a hollow heating and bending roll provided and having end walls, an inner end wallextending between the outer end wall of the roll and the combustion chamber and form with an inner annular combustion chamber mg an end chamber having inlet and outlet openings leading to the outside of the roll, an outlet opening leading from the upper part of the combustion chamber into-said end chamber at a point above'the level of said outlet opening in the end chamber an air inlet opening for admitting air to the interior of the combustion chamber, a burner extending into the combustion chamber, and means for supplying fuel to the burner.

10. In a machine for heating and bending metallic printing plates, the combination of a hollow heating and bending roll forming an annular combustion chamber having.

outer and inner annular Walls and provided With air inlet and gas outlet openingsfor' said combustion chamber, end Walls for said roll, an inner end Wall extending between the outer end Wall of the roll and said com- 2 bustion chamber and forming an end chamher having inlet and outlet openings leading to the outside'of the roll, a gas burner ex tending into the combustion chamber, a fuel v supplyrcondu it extending into the roll and connected with said burner, means for rotatively supporting said roll, a driving shaft located adjacent to the opposite end of the roll from said end chamber, means for rotatively supporting said driving shaft independently of the roll, and meansfor detachably connecting the roll With'the driving shaft and adapted to permit the removal of the roll fromits support independently of and Without removing the driving shaft from its support.

Signed at Chicago, in the county of Cook and State ofIllinois this 21st day of April,

' CHRISTIAN N. SMITH. 

